White roads are the ones they use for bike-routes in Germany, the main difference being that you have to look for the cycle route signs there and if you don’t have a route description you may easily miss them. Here in France you just follow the signs for the next village.
Admittedly they usually have racing bikes here. Amazing to me is how friendly the people are and how despite what everyone says, about them not speaking foreign languages – many try to speak English or German! Back to yellow roads – the ones I travelled on today had very little traffic but one of them was marked as an N-road and I was glad to get off it. Yellow roads have numbers on the maps so maybe they are not so bad after all!